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Lichen simplex chronicus (neurodermatitis) is eczema caused by repeated scratching; by several mechanisms, chronic scratching causes further itching, creating a vicious circle. Diagnosis is by examination. Treatment is through education and behavioral techniques to prevent scratching and corticosteroids and antihistamines.

Etiology

Lichen simplex chronicus is thickening of the skin with variable scaling that arises secondary to repetitive scratching or rubbing. Lichen simplex chronicus is not a primary process. Perceived pruritus in a specific area of skin (with or without underlying pathology) provokes rubbing and mechanical trauma, resulting in secondary lichenification and further pruritus. Lichen simplex chronicus frequently occurs in people with anxiety disorders and nonspecific emotional stress as well as in any type of underlying chronic dermatitis.

Pathophysiology

The underlying pathophysiology is unknown but may involve alterations in the way the nervous system perceives and processes itchy sensations. Skin that tends toward eczematous conditions (eg, atopic dermatitis) is more prone to lichenification.

Symptoms and Signs

Lichen simplex chronicus is characterized by pruritic, dry, scaling, hyperpigmented, lichenified plaques in irregular, oval, or angular shapes. It involves easily reached sites, most commonly the legs, arms, neck, and upper trunk.

Diagnosis

• Clinical evaluation

Lichen Simplex Chronicus

Diagnosis is by examination. A fully developed plaque has an outer zone of discrete, brownish papules and a central zone of confluent papules covered with scales. Look-alike conditions include tinea corporis, lichen planus, and psoriasis; lichen simplex chronicus can be distinguished from these by potassium hydroxide wet mount and biopsy.

Treatment

• Education and behavioral techniques
• Corticosteroids (most often topical but sometimes intralesional)
• Antihistamines

Primary treatment is patient education about the effects of scratching and rubbing. Secondary treatment is topical corticosteroids (eg, triamcinolone Some Trade Names
ARISTOCORT
KENACORT
KENALOG
NASACORT
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acetonide, fluocinonide Some Trade Names
LIDEX
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); surgical tape impregnated with flurandrenolide Some Trade Names
CORDRAN SP
CORDRAN
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(applied in the morning and replaced in the evening) may be preferred because occlusion prevents scratching. Small areas may be locally infiltrated (intralesional injections) with a long-acting corticosteroid such as triamcinolone Some Trade Names
ARISTOCORT
KENACORT
KENALOG
NASACORT
Click for Drug Monograph
acetonide 2.5 mg/mL (diluted with saline), 0.3 mL/cm² of lesion; treatment can be repeated every 3 to 4 wk. Oral H₁-blocking antihistamines may be useful. Emollients may also be helpful.

Last full review/revision September 2009 by Karen McKoy, MD, MPH

Content last modified September 2009